Maternal Physiology of Pregnancy

Abstract

During the course of pregnancy, the mother undergoes major physiologic and metabolic adaptations to accommodate the requirements of the developing fetus and to prepare for subsequent delivery, lactation, and care for her newborn infant. To some, to speak of the history of maternal physiology, in a volume devoted to the physiology of the fetus and newborn infant, may appear to be a contradiction in terms. However, as the fetus constitutes a portion of the maternal-placental-fetal ``complex'' or ``unit'' (Diczfalusy 1964), and its growth and development would be impossible without the mother, it suggests a rationale for this consideration. In addition, because optimal fetal developmental cannot occur in the absence of profound changes in the physiologic function of almost each of the maternal organ systems, metabolic, cardiovascular, respiratory, renal, neurohumoral, and others, such consideration is vital. The organs of the female reproductive system are among the most dynamic tissues in the human body. Even in the absence of pregnancy, from puberty to menopause, these undergo repeated cycles of growth and involution. To attain such plasticity, the reproductive tissues must respond to blood-borne signals (hormones, growth factors, and cytokines), as well as physical forces (mechanical and osmotic).